The present invention concerns a snap hinge closure of plastic with a lower part, and an upper part integrally connected by means of at least one hinge. The upper part is constructed as a cap or cover, as well as an element producing the snapping effect, which can be elastically molded, and which can be effectively connected with both parts during the closing and opening process.
Such closures have been available for many years, and in numerous forms of constructions. As examples of such closures, there should be mentioned those described in the U.S. Pat. Nos. 3,629,901; 4,386,714; and 4,573,600.
Closures comprise an essential part of the packaging of a product. This must be constructively adapted, depending on the type and form of the container onto which the closure is to be attached, and depending on the functional requirements placed on the closure. The physical characteristics of the product to be packaged also have an influence on the formation of a closure. Finally, the closure also has the function of individualizing the packaged product. All of these requirements have led to large number of closures, which are formed in many varied manners. Plastic closures are manufactured by means of typical mass production processes. High initial costs for the development and production of the necessary molds for injection molding are connected with this, which stands in direct contradiction to the desired diversity, which tends strongly to a reduction in the number of parts necessary.